This invention relates in general to dampers and in particular to a new and useful hydraulic damper intended for mounting drive engines of vehicles.
Bearings of this kind are employed for damping and suppressing vibrations which are caused by the travel and by balance variations of the engine or other moving parts, and have very different amplitudes and frequencies. What is sought is to make the damping effective over a maximum frequency and amplitude range, mostly in cooperation with a cushioning resilient element.
Aimed at this goal is German Pat. No. 32 35 700 disclosing a resilient rubber bearing in which a cushioning member with an element of a resilient material, and a hydraulic damper are integrated with each other. In this prior art design, a working space of the damper is provided below the resilient element, which is separated by a partition with throttling holes, from an equalizing space, so that upon resilient deformations of the cushioning member, liquid is forced from the working space through the throttling holes into the equalizing space, and in the opposite direction when the cushioning member regains its shape. The loads taken up by the cushioning member thus become fully effective against the hydraulic damper. In view of the operation of the damper within a large frequency and amplitude range, the partition of this prior art damper is made of a resilient material and mounted between stiff gratings and is provided with slots which, independently of each other, form movable portions of the diaphragm and, at the same time, a partial cross-sectional area of throttling. The other part of the throttling cross-sectional area may be formed by a bore. The throttling bore is designed for small amplitudes, so that with an increasing pressure and augmented vibration amplitudes, the cross-sectional area of throttling is continuously enlarged as a function of the available differential pressure between the equalizing and working spaces.